One in four U.S. children experience a mental health disorder with severe impairment and/or distress during their childhood. Further, high rates of exposure to violence and abuse are common among youth, particularly among those involved in the child welfare and mental health service systems. Violence exposure presents significant health and mental health consequences for children, with disparities in these experiences among racial/ethnic minority youth, and estimated costs exceeding $124 billion. While evidence-based treatments (EBTs) can prevent and/or reduce these negative effects, these treatments are still not the standard practice of care in many communities. Despite a recent proliferation of implementation research across a variety of settings, an ongoing challenge facing child mental health and child welfare professionals is how to transport and implement these EBTs so that they are readily available, accessible and sustained. The Learning Collaborative training model is being widely disseminated as a way to train community-based therapists to deliver EBTs. However, to date, the effectiveness of this model has not been demonstrated, nor has it been examined as a way to build and strengthen inter-professional relationships across the multiple professionals and agencies involved in providing services to children. Thus, to meet these public health needs, child welfare and mental health professionals must collaborate to improve the availability and sustainment of evidence- based practices for children. This project aims to test an extension of the Learning Collaborative Model, the Community-based Learning Collaborative model, which targets both clinical and non-clinical professionals in the child welfare and mental health service sectors as a way to build and strengthen inter-professional relationships and thereby improve coordination and delivery of evidence-based mental health treatment services. The proposed research offers the opportunity to capitalize on an on-going, statewide implementation project to generate evidence about implementation strategies needed to make EBTs more accessible to children. This study also provides data to inform an R01 effectiveness trial that will utilize a time-series design to rigorously evaluate the effectivenessof the CBLC model as a mechanism to improve access and sustained use of EBTs for children. The proposed mixed-methods study will involve participants (n=150) from two ongoing CBLCs being conducted as part of a statewide, foundation funded training initiative in South Carolina. The study will examine data collected pre/post, weekly and monthly over the 12 month active implementation period. Participants will be recruited for an 18 month follow-up period to examine whether inter-professional and inter-organizational relationships and use of EBTs are sustained over time. New quantitative and qualitative data will be collected during this sustainment phase. The proposed study will demonstrate feasibility and inform development of a large scale, multi-site study that will utilize a time-series design, to examine effectiveness of the CBLC implementation model.